Darwin IV
The fourth planet in the Darwin Binary System, Darwin IV is the homeworld of an impressive diversity of strange and unique life forms. It is 6.5 light years away from Earth's Solar System. Its binary system has six planets in all. Location, physical aspects and environments From an altitude of roughly 39,000 kilometers there can be a splendid view of the planet. With an equatorial diameter of 6,563 kilometers, Darwin IV is somewhat smaller than Earth. Its predominant color is dusky ochre, relieved by a sparse mottling of red and two crisply defined polar caps. The fourth planet and its two small moons circle the F-class binary at a distance of two AUs, taking two Earth years for one complete revolution. These two stars, quite different in size, are so close together as to frequently give the impression of a single star; this proximity almost completely eliminates the odd daylight optical effects that occur with a more pronounced double star. The Darwinian day lasts for 26.7 hours. Great open grasslands, which many believe to be ancient seabeds, are home to the overwhelming majority of Darwin IV's fauna. Many species have evolved into giants, a phenomenon believed to be a result of the planet's relatively low gravity (.6 of Earth) and the oxygen-rich atmosphere. The plains support a wide assortment of fauna ranging in size from small ground-burrowing scavengers, through the browsing tripedaliens and the predatory bipedalien liquivores, to the immense air-sifters, each delicately situated in its ecological niche. Darwin IV's largest and most famous life form belongs to another biome, the Amoebic Sea. This bizarre and misnamed region is blanketed by a gelatinous, 10-meter-deep organism covering almost five percent of the planet's surface; it is, in fact, the largest single colony animal known. The Amoebic Sea is home to the huge emperor sea strider, the enormous implausible organism seen stalking across an unnaturally smooth plain in the Yma probe's most celebrated sequence of transmitted images. Possibly because of the shock absorption and weight distribution qualities of the jellylike "sea," the sea striders have attained truly behemoth proportions. No other known creature rivals them in size. Darwin IV's montane region almost completely encircles the globe along the equator. While not impassable, the mountains present many problems for the planet's huge migratory herds. Storms and fogs claim thousands of individuals each year as they traverse the difficult and often icy mountain passes. As there are no oceans or seas on Darwin IV, the polar caps are the largest concentrations of water, in the form of ancient ice. These glaciers recede and advance with the seasons; as with Mars, the southern cap grows larger than its northern counterpart due to the prolonged southern winter. Evidence in the form of countless fossilized tree stumps scattered throughout the plains had lead the First Darwinian Expedition's chief botanist, Dr. Dorothea Kay the human, to postulate that Darwin IV was once a far warmer and more humid planet. At present the pocket forests account for only about five percent of Darwin IV's surface vegetation; even so, they presented the Expedition with its greatest challenge of exploration. Giant plaque-bark trees, with their massive trunks and twisted boughs surrounded by dense underbrush, made penetrating the forests via hovercone impossible. They had to content themselves with following the occasional stream a few hundred meters into the woods, or more often, simply circling and probing with their instruments. Ecology Flora Darwin IV's vegetation varies to a lesser extent than Earth's does. Succulents are by far the dominant class of plant life. The plains, arid as they are, are blanketed with thick tube-grass, a stalky pencil-thin succulent that grows astonishingly fast. This tube-grass and its cousins, fodderball weed and bladder reed, are the forage of the herbivorous plains-dwellers, providing a ready source of necessary moisture. In a sense the succulent-rich savannahs are the closest Darwin IV comes to true oceans, for the quantity of water trapped in the plants is vast. Only when approaching the mountains or forests do the succulents give way to other plant forms. Impenetrable underbrush, composed of sticklebush, whisperbrush and grenade vine, with its explosive pollen sacs, begins to dominate the landscape. These in turn give way to towering plaque-barks, the lords of the plant kingdom on Darwin IV and the principal tree of the planet's limited forestlands. The sub-polar region's flora is limited by the demanding environment. Low, ground-dwelling, lichen-like plants cover the almost frozen soil in a gray-green mantle that is broken by spidery, blue whipweed and tiny flowering polardots. This is a biome in which the mechanisms of nature are at their most fragile. In addition to the ground plants, Darwin IV possesses seemingly limitless quantities of tiny air plants, the aerophytes that make up the primary diet of the herbivorous air-sifters. Along with their animal counterparts, the abundant and varied microflyers, these aerophytes can, at times, darken the sky with their numbers. Fauna is an archetypal Darwinian bipedalien. Heavily muscled and very agile, it is capable of running down large game, either on its own or in hunting pods.]]Darwinian vertebrate morphology is quite different from its terrestrial counterpart. Most of Darwin IV's larger inhabitants fall into one of five classes: floaters and flyers (no real locomotive limbs to speak of); monopedaliens (one powerful saltatorial, ricochetal limb); bipedaliens (two-legged cursors); tripedaliens (three-legged cursors); and quadrupedaliens. Cursors are agile ground-runners, whereas saltators are hoppers. In some cases, such as most of the air-sifters, the rear limb has become a passive skid to support greater weight. Mass is usually supported by a hollow, thin-walled bone structure similar to that of the birds of Earth. This lighter structure predominates among Darwin IV's larger fauna and allows large predators to maneuver and run quickly; some raybacks, for example, have been clocked at almost 50 kilometers per hour and the fastest running of Darwin IV's animals, the gyrosprinter, frequently tops 90 kilometers per hour! Food-gathering and ingestion are, especially for predators, radically different from Earth's Carnivora mammals. Liquivores, which secrete digestive juices into their victims (dead or alive) abound. Absent are powerful, fang-lined jaws; in their place are a wide array of scalpel-sharp extensible tongues, each designed, as if by some master armorer, to pierce a particular skin or bony armor. With blinding speed these lethal tongues, guided by hyperdeveloped accelerator muscles, can pass completely through a medium-sized prey animal, injecting paralyzing digestive fluids on impact. Actual feeding, with broken-down body fluids being siphoned through the tongue, often begins even while the prey is still living. One of the most obvious and significant point of departure from most of Earth's fauna is the planet-wide lack of true eyes. Optical sensory organs are absent, having been supplanted, through eons of evolutionary selection, by a battery of sonar and infrared faculties. These senses are, in most places, complemented by a sophisticated lateral line system of sensitive, subcutaneous pressure receptors which, in conjunction with shows the forward sensory package and tongue sheath, which at a distance can look eerily like a head with eyes.]] numerous, tiny infrared receptor pits, gauge both the surroundings and the proximity of other creatures. In addition to this somewhat difficult to discern receptor system, Darwin IV's creatures possess biolights, heat-radiating bioluminous spots that appear quite vivid to infrared sensors. These light arrays (which probably aid in herd member or enemy identification) are especially important during courtship, when subtle color shifts and the dramatic overall brightening the Expedition called "flaring" occur in the mating pair's biolights. This mating beacon can attract mates from as far away as 10 kilometers. To the creatures of Darwin IV, temperature, not visible light, is the sole means of determining the difference between night and day. As a result, the concepts of light and dark are meaningless, and activity is predicted on relative temperature variations. Temperature regulation through metabolic activity and insulating layers of fat has eliminated the need for fur in Darwin IV's temperate climate; indeed it is doubtful whether any denizen of Darwin IV even has fur, as the sonar and heat transmitters and receptors must remain uncovered. 's fore-and-aft symmetry confuses predators, many of which attack it in high-speed power-dives. This symmetry prevents the predator from knowing until the last second which way the creature is heading.]]Sonar projectors exist in all of Darwin IV's inhabitants. Though they vary in size and form, the basic structure is the same from species to species. A large frontal cavity filled with dense fluid serves to focus the ultrasonic pings produced by a complex larynx-like organ. Because of the high frequency of the sonar and its concomitant short range, Darwin IV's creatures are forced to ping in a steady stream, making the planet a rather noisy place to one able to perceive the signals. These highly developed senses endow their bearers with a very precise and complex view of their world. The best guess is that animals who had developed these sensory organs proved too formidable for those creatures with rudimentary optical abilities struggling for life and dominance in Darwin IV's thick, primordial mists. Now the mists are gone - but so are the optically-sighted animals. With notable exceptions (such as the sac-backs), most higher organisms are hermaphroditic, and mating can lead to impregnation of both partners. The participants' genitalia are always identical: a long suspended tube hanging horizontally behind. During mating, these fleshy tubes unroll about halfway and clasp each other. Fine grooves or channels carry sperm/egg mixture back and forth, mingling it for as long as 10 minutes, depending on the species. Coupling is achieved in a dorsally aligned attitude, which, it has been suggested, allows for mutual defense. The Expedition saw many matings continue while the participants fought off attackers. Darwin IV's higher life forms are not mammalian. Though they are for the most part warm-blooded, they do not nurse their young. Young can be born alive, as with the daggerwrist and the sac-back, or can hatch from eggs laid underground, as with the grove-back and keeled slider. Great variation exists as to the amount of care and attention young receive immediately after birth. Generally, the egg-born young are precocial - that is, able to fend for themselves - and live-born young are altricial, or in need of care. Exceptions to this rule exist, such as the nurturing keeled sliders whose egg-born, altricial young are in the parents' tow for about two years and need much attention. Strange crossovers also exist, as in the case of the emperor and lesser sea striders. The eggs of these huge creatures are dropped onto the "sea's" undulating surface, where they remain until they hatch. Upon emerging from the eggs, the nymphs must find their way back to their parents until they are fully independent. Certainly the most remarkable of Darwin IV's assortment of wildlife is the floaters. They have constantly evoked a sense of otherworldliness in Yma and human alike. These magnificent beasts - huge, typically finned, and usually covered with breathing float-bladders - dot the sky sometimes in great sailing herds, gliding lazily through the warm breezy air. Manufacturing hydrogen from water vapor in the atmosphere, through some form of organic electrolysis, the floaters drift ceaselessly, certain species descending to the surface only to hunt. At night their beautiful arrays of biolights can be seen drifting silently overhead. They are generally bizarre, placid creatures of poetry, graceful and ethereal. Exploration An expedition to planet Darwin IV was carried out by humans and Yma in the year of 2358 (preparations began in 2355) and lasted about three Earth years. They attained orbit above Darwin IV on January 6, 2358. During this time the planet was explored and its unique lifeforms were studied. They covered a considerable amount of territory; but by no means did the planet yield more than a fraction of its secrets. However, one of the objectives of the mission was to have the littlest impact possible on the planet's natural environment. They Expedition left Darwin IV on Marsh 24, 2361. Since the Expedition's departure the entire Darwinian system has been off-limits and is patrolled continuously by Yma robot drones. Conservation Security Even though the First Darwinian Expedition of humans and Yma has left Darwin IV, the Yma had left a titanium stele on the plains as the guardian and monitor of the planet. Its silver sides, etched with the names of the Expedition's personnel, hide a myriad of microsystems linked to a planet-wide system of intruder alerts. The robot police-drones patrolling the Darwin system will regularly pick up and forward the accumulated data. Darwin IV shall be so well protected. Sources *''Expedition: Being an Account in Words and Artwork of the 2358 A.D. Voyage to Darwin IV'', by Wayne Barlowe Category:Alien Animals Category:Darwin IV species